Pipe coupling



Jul 22, 1947. E 2,424,436

\ PIPE COUPLING Filed April 13, 1945 2 Sheets-Sheet 1v 4 Inventcpf:Wi|bUTD.C Pate]? Attorney.

July 22, 1947.2 w. D. CRAT'ER PIPE COUPLING Filed April 15, 1945 1 2Sheets-Sheet 2 Wilbur" D ntor:

.CPate )M/M s Attor n ey- Patented July 1947 rrrs COUPLING XI n 'WilburD. can, Peabody, Mesa, assignor It General Electric Company, a;corporation of I Application, April 13, 1945, seriamaaa132 Thisinvention relatesjto pipe couplings, particularly simple couplings whichmay be quickly and easily installed and disassembled and which can beused repeatedlmfll I I a I 1 I An object of the invention istofprovidea. simple light-weight coupling especially suitable for thin-walledconduits made of sheet metal.

A further] object is to' provideIa coupling ca pable of producing verygreat axial forces by toggle action to hold the conduit sectionstogether, while requiring the applicationoia minimum force in making upthe, coupling to produce the desired axial forces on the pipeends.

- 6 Claims (01. ass- 129) wardly andaxially towards each other. The endsof the split band I have welded thereto attachment members 4, each ofwhichis provided with two axially spaced cylindrical Ilugs 5 arranged ateither side of the band I with the centerlines of thefcylindricalopenings through the lugs lying I as nearly as possible in a planetangent I to the band I at the location 2. Suitable thread- Anotherobject is the reduction of the friction I forces between, the movingpartsof a toggle-type pipe connection.

c A still further object is the provisionof a. unitary couplingdevicewhlchjis easy to install and disassemble in inaccessible locationsand. where;

spaceis at a premium. I I

Another object is to produce a pipe coupling which can be progressively,tightened, within limits, if the conditionsfencountered in servicetendto cause loosening of the coupling or leakage through the pipejoint. I x V Another object is the provision of a resilient pipecoupling device having no parts which are permanently deformed in use,so that it can be disassembled and re-used repeatedly without re-Iplacement or repair of any parts. I

Further objects and advantages will be apparent from the followingdescription and the appended claims taken in connectiohlwiththeaccompanying drawings, in whichFig. lis a side view, partly in section,of a pipejoint embodying;

a coupling made inj accordance wlth my invention; Fig. 2 isa frontview,also partly in section, of the joint shownin Fig. 1; Fig. 3 isapexjspective view, partly broken away, of the Icoupling shown in Figs. 1and 2; Fig; lishfperspectiye view, partly broken away, of a modifiedform of my invention; and Figs. 5 and;6 aresectional views illustratingthe method of operation of the modification-shown in Fig. 4. I

In Fig. 1 the cylindrical conduitend portions 8 and 9, represented asthin-walled pipe made of sheet metal, are provided withcircumferentially extending flanges I0 and II, represented as separaterings L-shaped in cross section and having one leg welded to the end ofthe pipe section while the other legs form radially extending flanges I2and I3 adapted to be engaged ed fastenings such as the,socketIhead bolts6 are disposedthrough the lugs so thatthe attachment members L can bedrawn together by tightening the nuts 1.

Round, socket head ,bolts are advantageous because square nuts can thenbe jused, so arranged that the corners engage the band and hence nowrench need be applied to the nuts. Tightening is done rnerelyby turningthe bolt head. ;With this arrangement of the threadedfastening s theline of action of the tenfsion forces produced by the bolts 6 is in oras close as possible to the plane of the ends of the split band Itherefore there is no bending momerit exerted on the split ends tendingto move themradially inward so as to bind on the pipe flanges I0, II.

ent, would produce excessive friction which would Such bending moments,if presmake the coupling diflicult to install. I

Slidably disposed within thecircumferential channel definedjby the bandI and the depending "jof resilient finger portions I5, each of whichedge portions 3 are a number of'segmental members Hfprovided with twocircumferential rows extends radially inward and axially towards acorresponding finger in theother row. Each fingerfliasj anend portion I6arranged toengage the outer f-ace of one of the radially extendingflanges I2, I3. I The structure of the band I {attachment memher 4, andresilient segments I4 can be better seenirr the perspective view of Fig.3. The attachmentmember 4 may be secured by "spot-welds IT to the bandI, and the lugs 5 may be formed by laterally extending portions bentaround and uIspot welded. to the member 4 at I8. The lugs 5 I may befurther bent backward, from the position by my pipe coupling. I Thecoupling consists of a band I split at the location 2 and havingcircumferential edge portions 3 bent radially inrepresented in Fig. 3,so that the center line of the lugs is'exactly in a planetangent to theband I. Each segment I4 may be made by making suitable saw cuts in theedges of dflat piece of,,sheet metal and then bending it up to thecrossIsection illnstratedin Fig. 1. Atom or both ,ends of IeachIsegmentM an additionalcut 20 is made so as Itoproduce, themesilient end portionZI, whichIis slightly bent circumferentially away from the, rest of thesegment I4. It will be seen that this resilient end portion 2|resiliently abuts against an end ofv the adjacent segment I 4 so as tospace the segments it slightly apart before the bolts 6 are drawn up,while permitting some circumferential readjustment and compression ofthe segments II as the fastenings 6 are tightened up. This provision forsome circumferential movement of the segments H relative to the band Ihelps to reducethefriction forces generated when the coupling is beingtightened up, thereby making installation easier. The edges of the bandI at the ends adjacent the split 2 may be crimped as at ill in Fig. 2 toprevent the segments 14 sliding out of the bandl.

It will be observed that the band i holding the resilient segments II isa self-contained unit which can conveniently be handled without dangerof losing any of the component parts from the assembly. When the.coupling is used to connect thin-walled pipes made of sh'eet metal, theparts of the coupling may also be made of comparatively thin resilientsheet metal such as stainless steel.

If the couplingis made of thin resilient sheet metal as suggested, thenit needs to be split at only one place, the location 2, its resiliencypermitting the split ends to be opened up sufilciently to be slippedaround the flanges [2, I3. The bolts 6 are then inserted through thelugs and the nuts I assembled. Turning bolts 8 by a tool inserted in thesocket head produces a circumferential hoop tensionin'the, band Icausing it to contract. It will be seen from a consideration of thecross section of the coupling shown in Fig. 1 that contraction of theband I causes the resilient flngers IE to be de-.

flected toward the band I, producing a toggle action which causes thefinger end portions, Hi to be forced tightly into axial engagement withthe sides of the flanges i2, it. By reason of this toggle action, themoderate force exerted by the fastening devices 8. is capable ofproducing very considerable axial force securing the pipe flanges l2, l3together. Also with the'toggle action, each increment of motion of thelugs 5 towards each other produces a greater-axial, tightening force onflanges l2 and I3 than did the preceding increment.

It will be obvious that any suitable type of gasket (not shown) may beinserted between the flanges l2, l3 before the coupling is assembled.

' However, the effectiveness of thecoupling is such that for manyapplications no gasketmay be needed.

It will be seen that the coupling represented the inner circumference ofthe segments H is be installed and disassembled repeatedly withoutdepreciation of the eflicacy of the device.

It may also be noted'that this coupling is comparatively easy to tightenup because there is a minimum of rubbing contact between relativelymoving parts of the assembly, most of the necessary relative movementbeing accommodated by resilient deflection of. the members. Relativeaxial movement of the flanges l2, l3 is accompanied by resilientdeflection of the fingers l5, while circumferential movement of thesegments H' relative to each other and to the band i are accompanied bydeflection of the resilient end portions 2|. Because of the reduction inthe friction forces produced in tightening up the coupling, it can beformed as a single assembly split and provided with fastening devices 6at only one place (2 in Fig. 2).

My coupling is particularly well adapted for use in power-plantinstallations in aircraft, where an enormous quantity of, mechanicalequipment must be compressed into the smallest possible space whilestill permitting maximum ease of accessibility to the various componentsfor maintenance and service purposes. My coupling can be readily spreadapart and slipped around a pipe joint so located in a power plantinstallation that the joint is accessible at only one small portion ofits circumference. The ease with which this couplingis made up anddisassembled 'makes it particularly adaptable to aircraftpower-plant'swhere it is desired to be able to quickly remove componentsfrom the installation for repair and replacement.

"My coupling is readily adaptable to such applications as the air intakeducts of an aircraft power-plant, as well as the conduits used for thehot products of combustion from an engine. It can readily be produced ina wide range of sizes, being equally adaptable to small diameter exhauststack joints and. very large joints, as for instance the dischargeconduit of an aircraft jet propulsion engine.

In the modification of my pipe coupling shown in Figs. 4,5, and 6, theouter band 23 is formed with an inverted U cross section, andtheresilient segments ll of Fig. 3 are replaced by a, single innerband'IZ having edge portions 24 welded to corresponding edge portions ofthe outerband 23: The band 22 has a substantially W-shaped cross.section with the mid-portion forming an inverted U-shaped bridge 25arranged to straddie the outer edges of-the pipe flanges l2. II in themanner shown in Fig. 6. The resilient finger portions [5 are formed bythe saw cuts I8, as

in the modification of Figs. 1 to 3 inclusive.

portions of the U-shaped bridge 25 into engagecontracted substantiallyinto contact with-the outer circumference of the flanges l2, Il with thefinger portions l5 substantially flat againstthe under side .of thesegments ll.

It should be noted that in normaluse none of the parts of the couplingare permanently dement with the outer faces of the flanges l2, l3. WhileI have illustrated a particular form of fastening device (bolt 6 andlugs 5) for drawing, together the ends of the couplin assembly, it

v will be apparent that toggle type hasps such as used in trunklids andmany other kinds of fastenersmay be used.

It will be seen that my invention provides a simple, light-weight,unitary pipe coupling which can be easily applied, re-tightened inservice, readily removed, and repeatedly re-used.

What I claim as new iie to sec'ure by Letters Patent of the UnitedStatesis:

l. A re-usable quick-detachable coupling for two pipe sections havingcircumferential flanges at the abutting ends, comprising a split clampband assembly including two parallel axially spaced annular rows ofresilient finger portions. each finger making an acuteangle with theplane of the band and each, having tan end portion in axially spacedopposed relationato the endportion of a corresponding finger in .theother row, and adjustable securing means associated"with the ends of theclamp band and arranged to produce hoop tension in the band so that theend portions of the fingers in the two rows canbe forced axiallyagainstthe respective outr faces of the pipe flanges to clamp the flangestightly together by toggle action of the fingers.

2. A re-usable quick-detachable upling for two pipes havingcircumferential nges at the abutting ends, comprising a splitibahdassembly including two parallel axially spaced annular flanges, eachsegment having also a resilient end portion arranged to engage theabutting end of the next adjacent segment so as to space the segmentswhile permitting limited circumferential contraction of the outer band,and adjustable securing means associated with the ends of the splitouter band and arranged to produce hoop tension to cause contraction ofthe band so that the ehd portions of the two rows of opposing fingerscan be forced axially against the respective outer faces of the pipeflanges to clamp the flanges tightly together by toggle action of thefingers.

5. A re-usable quick-detachable coupling for two pipe sections havingcircumferential flanges at the abutting ends, comprising an inner splitband with two axially spaced annular'rbws of resilient finger portionsformed integral with the band and each extending in an inclineddirection radially inward and axially toward the other row, an outersplit band surroundingthe inner band and secured rows of resilientfinger portions, each finger ex t,

ten-ding in an inclined direction radially inward and axially toward theother row, and fastening meansiassociated with the ends of the splitband and arranged to produce hoop tension in the band so that theradially inward portions of the resilient fingers can be forced intoengagement with the outer faces of abutting pipe flanges to securelyclamp the flanges together by toggle action of the fingers. I}

3. A re-usable quick-detachable coupling for two pipe sections havingcircumferential flanges at the abutting ends, comprisinga split outerband with circumferential edge ions extending radially inward and towareach other, a plurality of arcuate segments heldin the circumferentialchannel formed by the outer band, each segment having two axially spacedrows otresilient finger portions formed integral with the; segment, eachfinger extending in an inclined direction radially inward and axiallytoward the other row, the fingers in both rows having end portionsadapted to engage the respective outer fkies of the pipe flanges, andadjustable securing means 1 associated with the ends of the split outerband and arranged to'produce hoop tension tgl cause contraction of theband so that the endwtions of the two rows or opposin fingers canbeforced axially against the respective outer facea of the pipe flanges toclamp the flanges tightly together by toggle action of the fingers. r

4. A re-usable quick-detachable coupling for two pipe sections havingcircumferential flanges at the abutting ends, comprising a split outerband itgith circumferential edge portions extending radially inwardandtowards each other, a plurality of arcuate segments held in thecircumferential channel formed by the outer band, each segment havingtwo axially spaced rows of resilient finger portions formed integralwith the segment, each finger extending in an inclinedaiirectionradially inward and axially toward the: other row, the fingers in bothrows having endrportions adapted thereto to form a unitary assembly, andfasteni g means associated with the ends of the outer split band andarranged to produce hoop tension so as to contract the bands and forcethe opposing radially inward portions of the resilient fingers intoengagement with the outer faces 6. A re-usable quick-detachable couplingfor tiwo pipe sections having circumferential abutting anges, comprisingan inner split, band witlrl-a s bstantially W-shaped cross-section, thedepending end portions ofthe W beingshaped to define two axially spacedannular rows of resilient finger portions each finger extending in} aninclined direction radially inward and axially toward, the other row,the middle portion of the W forming a circumferential channel openinginwardlyand adapted to surround and engage the edge and outer sideportions of said abutting flanges, an outer split band surrounding theinner band and secured to the outer edges thereof to form a unitaryassembly, and fastening means associated with the ends of the outersplit band and arranged to produce hoop tension so as to contract theband and cause the U-shaped midportion of the inner band to firmly seaton the outer circumferential surfaces of the flanges and the resilientfinder portions to force the flanges axially together by toggle actionof the fingers.

I D. CRA'I'ER.

REFERENCES crran The following references are of record in the flle ofthis patent:

UNITED STATES PATENTS Number Name Date 1,937,881 Fisher Dec. 5, 1933FOREIGN PATENTS Number Country Date 165,262 Great Britain June 30, 1921

